Highway-crossing signal



' Aug; 19, 1930.

R. A. M CANN HIGHWAY CROSSING SIGNAL Filed Jan. 28, 1950 INVENTORIPatented Aug. 19, 1930 UNITED STATES PATENT OFFICE- RONALD A. McCANN, OFSWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE .UNION SWITCH & SIGNAL COMPANY,OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIAHIGHWAY-CROSSING SIGNAL Application filed January 28, 1930. Serial No.423,961.

My invention relates to highway crossing signals, and has for an objectthe provision of means for controlling a signal at the junction of ahighway and a single track railroad without the necessity for utilizingan inter locking relay.

It will describe one form of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagram matic view showing one form ofapparatus embodying my invention.

Referring to the drawing, the reference characters 1 and l designate thetrack rails of a stretch of single track along which traffic moves attimes in both directions. These rails are divided by insulated joints 2to form two track sections A-B and B-C, and the track is intersected bya highway H at substantially the junction of these sections. Located atthe junction of the highway H and the railroad track, is a highwaycrossing signal E, which, in the form here shown is an electric bell.

Each track section is provided with a track circuit, comprising theusual track battery 3 and the usual track relay T the relays for thesections A-B and BC, being designated T and T respectively.

The highway crossing signal E is con trolled by the track relays T and Tand by a signal relay D. Relay D has two operatin windings D and Dneutral contacts 6 and 7, and a polarized contact 8. The parts of thisrelay are so adjusted that when both of the windings D and D areenergized, the neutral armature is released, whereas when only onewinding or the other is energized, the neutral armature closes and thepolar armature swings to one position or the other according to which ofthe windings is energized. When winding D alone is energized, polarcontact 8 is swung to the left, whereas when winding D alone isenergized, polar contact 8 is swung to the right. The relay D is furthercharacterized by the fact that the polar armature operates before theneutral armature when either winding of the relay becomes deenergized.

As shown in the drawing, both of the track sections are unoccupied, sothat both of the track relays T and T are energized. Winding D of relayD is, therefore, energized by a main circuit which passes from a batteryF, through the front point of contact t of track relay T and winding Dto battery F. Winding D is energized by a similar main circuit whichpasses from battery F, throu h the front point of contact 5 of track reay T and winding D to battery F. The neutral front contacts of relay Dare, therefore, open so that the circuit for the highway crossing signalE is open at contact 6.

I will now assume that a train moving to the right enters section AB.This will cause track relay T to open, thereby opening at the frontpoint of contact f the main circuit for winding D with the result thatwinding D alone will be energized. This will cause the front neutralcontacts 6 and 7 to close, and it will also cause polar contact 8 toswing to the right, and inasmuch as the polar armature responds beforethe neutral arma ture, winding D will remain deenergized. The closing ofthe neutral armature will close the circuit for the signal E at frontcontact 6, which circuit will be obvious from the drawing withoutexplanation. When the front end of the train enters section BC, it willdeenergize track relay T whereupon an auxiliary circuit for winding Dwill become closed, which circuit passes from battery F, through neutralfront contact 7, polar contact 8 in the right-hand position, back pointof contact 5 of track relay T and winding D to battery F. When the rearend of the train passes out of the section A-B, the main circuit forwinding D will again become closed through the front point of contact 4of track relay T Both windings D and D will then be energized, with theresult that the neutral armature of relay D will release and so theoperation of the crossing signal E will stop. When the train passes outof section BC, track relay T will again become energized, and the partswill be restored to the positions in which they are shown in thedrawing.

When a train moving toward the left passes through the stretch of trackshown in the drawing, the operation will be the same, ex cefit thatpolar contact 8 will be swung to the 1e as soon as track relay T opens,with the result that an auxiliary circuit for wind- 5 ing D will becomeclosed when the train enters section AB, and so the operation of thecrggs ng signal will cease as soon as the rear end of the train passesout of section 10 Although I have heroin shown and de scribed only oneterm of apparatus embodying my invention, it is understood that variouschanges and modifications may be made therein within the scope of theappended claim without departing from the spirit and S ,qf. my in entin.

ggfllllg thus described my lnvention, What n hqb mi e t a i i c n 9 wayrack, a h Way ntersectm said Week ubstant the unction 0 said sect onag atriwk c}rcu t' 1nclud1ng a track 91 c of d s n s slgnal relay having twooperati eifi'wlndmfis and a neu- 55 tra matureas w es 9, paler armature,garaqtenzed by he fa t t p at when b t w pi gwgs are, energmed theneutral armature,

is re eased whereas when only one windmg or; the other is, energiqed theneutrahar'ngmsq ture 'closes and the polar armature sw ng? to oneosition or the other accord ng tow ich win g is ener 'zqd, a circuit forthe first Winding P said, s1 relay including a". sou e. f current a" va, front contact of a h r 's z e ax a e (refit e second wlnding of saids gnal relay including said source and a front contact of the 86 mlfrapk relay, an 'anxihary clrcuit for ihsfir fi m s ed s n relay includmsaid source and a hack, crintact of the track relay as well we rontneutral contact of the signal relay and a polar contact f the signalrelay which closes when only he winding is energized, an auxil- 5 larycircuit for the second winding of said signal relay includin said sourceand a back contact of the secon' track relay as well as a front neutralcontact of the signal, rela and a polar contact of the si 1181 relaywhich 50 closes; when only the secon windin is en ergizad, and a highwaysignal locate at the intersection of said railway track, and saidnfinity and ntrolled by said signal relay.

fjtestimony whereof I afip'x In si nature. fit RONALD A. c0 NN.

